1. Technological Field
This technical disclosure pertains generally to wireless data links, and more particularly to a method of eliminating a power amplifier from the transmitter chain in a wireless data link, while overcoming the effects of ambient reflections.
2. Background Discussion
WiFi and WLAN technology (IEEE 802.11 a, b, g, n, ac, ad) have been very effective in the mobile market (e.g., phones, tablets and portable gaming). However, the high power consumption of existing WiFi transceiver technology is proving to be unsuitable for the emerging wearable device market (e.g., Google Glass, Samsung Galaxy Gear, Apple Watch, etc.). One core reason why power consumption is limited is because the WLAN transceiver (currently implemented at either 2.4 or 5.83 GHz) requires a power amplifier device to generate power levels suitable for transmitting a WiFi signal to a base-station or router. State-of-art power amplifiers remain only 10% efficient in typical cases with best reported performance not exceeding 15%. Thus, in order to generate the typical 100-250 mW required to send a WiFi signal, the device must consume on the order of 1000-2500 mW, definitely not compatible with wearable products where the battery is so small and simply cannot support such high power levels.
In a prior application by the inventors, a technology was described that eliminated power amplifiers from a remote module (e.g., wearable device) configured as a reflection module, thus enabling implementation of a WLAN or WiFi link that consumes a factor of 10-100× (one to two orders of magnitude) less power. However, the overall communication performance could still be heavily limited by receipt of ambient carrier reflections which appears as an in-band signal blocker (blocking signal) or jammer.
Accordingly, a need exists for a reflection module that eliminates the need of a power amplifier while it overcomes the effects of ambient reflections.